jack rabbits were positive for. RMSF using the fluorescent antibody test. The black- ..... in wild populations difficult. Al- though reported from counties to the west,.
Journal
of Wildlife
Diseases,
26(1), Disease
© Wildlife
Serologic Survey of Selected Zoonotic Disease Black-Tailed Jack Rabbits from Western Texas
Agents
1990, pp. 107-111 Association 1990
in
Scott E. Henke, Danny B. Pence,2 Stephen Demarais, and James R. Johnson,3 1 Departmernt of Range and Wildlife Management, Texas Tech University, Lubbock, Texas 79409, USA; 2 Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA; 3Texas State Department of Health, Region 2, Lubbock, Texas 79424, USA
A
ABSTRACT:
of Rocky
serologic
Mountain
survey
for
the
tant zoonoses in the urban environment. Thus, the objective of the present study was to determine the prevalence of certain
agents
fever (RMSF) (Rickettsia rickettsii), Borrelia spp. including the causative agent for Lyme disease (Borrelia burgdorferi), and plague (Yersinia pestis) was conducted on blood samples collected from 30 and 46 black-tailed jack rabbits (Lepus californicus) from an urban environment in Lubbock, Texas
(USA)
lowing
spring
ters
to
the
during agents
respectively. in plague
of
close
proximity
United
notic
reservoirs
RMSF,
least
the
in
one
potential this
spotted
fever,
sylvatic
reservoir,
Yersin
The black-tailed ifornicus) occurs western highly
United adaptable
ban populations to the higher throughout
plague, ia
mamzoo-
survey,
pestis.
jack rabbit throughout
living density its range
ner, 1986). Although ed as a reservoir
it
for
Roshi
and ur-
and
this
mammal
Will-
for
sacks, eutha-
intraperitonea!
injec-
solution Illinois
(Taylor 62525,
samples were taken with a 12 cc syringe
Ltd.,
plague was Type I paper
Tokyo,
Japan).
portion of the Nobuto in blood, removed
blood samples, jack a white procelain ether-soaked gauze
has been implicatcertain arthropod-
as a reservoir
ml
via and
thropod
parasites.
lected ceps
impor-
directly and
Tissues 107
stored from
jack
in vials the
The
ab-
collection
of
rabbits were placed in closed container with to anesthetize the arEctoparasites
from
tested (Toyo
paper was and allowed
to air dry at room temperature. Immediately following the
transmitted zoonoses (Parker et a!., 1939, 1951; Philip et a!., 1955), there has been little emphasis placed on the importance of
urban
in gunney area and
euthanasia Decatur,
to sylvatic Nobuto Strip
Kaisha,
sorbing immersed
in close proximity human populations (Chapman
a 1.5
Two blood puncture
antibodies with the
(Lepus calthe south-
States; it is a common species with sizable
their
an
serum was collected and stored on wet ice. Thick blood smears were prepared by placing one drop of whole blood on a microscopic slide and laking it with a wooden applicator stick until dry. The presence of
Texas.
serologic
and in
an 18 ga needle. One whole blood sample containing EDTA was stored on wet ice while the other blood sample was centrifuged at 1,400 rpm for 15 mm, and its
pop-
important
western
in
southwestern of
were placed to a holding
with
USA). a heart
jack
words: Borrelia spp., borreliosis, blackjack rabbit, Lepus californicus, Lyme Rickettsia rickettsii, Rocky Mountain
disease,
urban
indicate
at
the
living
agents
vectors Texas.
Texas Tech University camTexas; 33#{176}35’N, 101#{176}54’W).
tion of T61 Pharmaceuticals,
12
from
using
human
the
populations
for
disease,
Key tailed
results
urban
ticks
black-tailed
of
nized
in
18
species density
areas
Our of
of
RMSF
The
higher
many
States.
importance as
Four
wildlife
to
in
ulations
blood
on the (Lubbock,
Jack rabbits transported
detected
removed
test.
is a common
pus
and/
whole
not
for
tively,
rabbits, were
disease
arthropod in western
Thirty and 46 black-tailed jack rabbits were live-trapped during 1 to 7 December 1987 and 30 April to 8 May 1988, respec-
ti-
antigens
zoonotic
associated locality
were
jack
or
were
positive
antibody
rabbit
tissue
sampled.
were
fluorescent
the
selected
fol-
(rickettsiae
parumapertus)
rabbits
mal
the
rabbits
(Dermacentor
of
associated
antibodies
jack
76
1%
the
borreliosis
organisms their
any
and
Antibody
and
of 28 and nor
samples;
jack
RMSF
Neither
detected
1987
respectively.
of
spirochetes)
the
winter
1988,
in sera
detected or
spotted
heart,
rabbits on
wet
spleen,
were
col-
with
for-
ice. liver
and
108
JOURNAL
OF WILDLIFE
DISEASES,
VOL.
26, NO.
c Cl 0
1) be
E
-
2
.
0
placed buffered
blood,
sera,
thick
blood
tissue
samples
and
plernent-fixing
-5
-
vials conAll whole
smears,
and
ar-
were
tested
for
antibodies
ettsii (Lane tibodies to
0
-
cI
in separate formalin.
either disease agents, antigens and/or antibody titers against R. rickettsii and Borrelia spp. at the Texas State Department of Health (Austin, Texas 78767, USA). Sera from jack rabbits were examined for corn-
1-’
.,
were 10%
thropod
c.c
-
kidney taming
,:
0
-‘
1990
e
,:;
S
1, JANUARY
against
R.
rick-
et al., 1981) and against anBorrelia spp. by indirect
C.) Cs
immunofluorescence
.-
(Russell
et a!.,
1984).
(
,
(C(CcC
N
Z
N
N
oc
ci ..
C
cI
-5
Serum antibody titers were considered significant at 1:128 for R. rickettsii and Borrelia spp. Ticks were inspected for rickettsiae and spirochetes by direct immunofluorescence of individually dissected midgut tissue (Burgdorfer and
[f:
Lackman, 1988) and hernolymph
,
.
as c
5)
be Cs
I
> -‘
c Cs
.c
.
-
so so
C
.0
..
tempts were
body
C
-
>
-
,
cc
Z
.
CC
C
‘
-
isolate
spirochetes
blood medium dorfer,
and
were
smears (Lane
Nobuto
0) -
USA) pestis. three
. a a
o
o
COC’DC’D
o
-
a
whole
Type
Branch, Collins,
and tested for Each Nobuto to four parts
direct immuBurgdorfer, I papers
were
Centers for Colorado
Disease 80522,
antibodies against Y. paper was cut into and soaked in phos-
phate-buffered solution (pH = 7.2) for 60 mm at room temperature to extract the antibody components; the suspensions were tested by a passive hernagglutination test (Wolff and Hudson, 1974).
C.) e-.
from
by and
Strip
sent to Plague Control (Fort
C.) C
made
tissue inoculated into BSK II (Barbour, 1984; Lane and Burg1988), and to identify spirochetes
1988).
C’,
a
to identify rickettsiae from tissue made by indirect fluorescent antitests (Lane et a!., 1981). Attempts to
on thick blood nofluorescence
C” 0
C
the At-
..
C’
-
1960; Lane and Burgdorfer, for rickettsial pathogens by test (Burgdorfer, 1970).
o
Of
the
76 jack
rabbits
tested,
28 and
1%
to
the
C.)
‘o 0
-
a
a C/)
positive
antibody
titers
. .
a
c.
agents
,
,a
nc.
aaCC .
‘
.
‘
.
Es
showed
-#{176} .0_C -#{176}
z z
5
a
tively RMSF
of
RMSF
respectively, winter; these spectively,
and
borreliosis,
(Table 1). Percent and Borrelia spp. in jack values in
jack
respec-
antibody were 33
titers to and 0%,
rabbits were 24
captured and 2%,
rabbits
captured
in rein
SHORT
spring. Only one jack rabbit antibody titers to the agents and borreliosis. Spirochetes or rickettsiae lated imens. ed
had positive of both RMSF were
not
iso-
from any of the tissue or blood specPlague antibodies were not detect-
in any
of the
76 jack
Ticks or fleas were jack rabbits captured
rabbits
tested.
not found on in December
the 30 1987;
however, 18 ticks were recovered from 12 of 46 jack rabbits obtained in spring 1988, including 7 Haemaphysalis leporispalustris and 1 1 Derrnacentor parurnapertus. Of
these
ticks,
tibody
tested test
ettsiae ticks
were by the
(22%)
four
positive for the
flat
D.
parurnapertus
by the fluorescent agent of RMSF.
not detected hemo!ymph
anRick-
from any of the test (Burgdorfer,
1970).
Although from
the
rickettsiae tissue
were
or blood
serum antibody titers jack rabbits had been ettsii. Positive RMSF reported in the sera
not
samples,
isolated the
suggested exposed antibody of 26 of
high
that the to R. ricktiters were 542 black-
tailed jack rabbits in rural Kansas (Pagan et a!., 1961) and in 37 of 135 black-tailed jack rabbits in California (Lane et a!., 1981). Such with
a large antibodies
environment man population
percentage of to R. rickettsii such
as Lubbock, >200,000)
jack rabbits in an urban has
Texas not
(hubeen
documented previously. An urban outbreak of RMSF was reported in 1987 when four persons contracted the disease in city parks in the et a!., 1988). Dermacen mit virulent ettsii (Parker
Bronx,
New
(USA)
(Salgo
of
Dermacentor americanum, found on humans
and James, 1979), more commonly
bits (Parker et al., 1939; there is the possibility of from black-tailed jack hosts for both species of Mountain spotted fever
can transof R. rickto the over-
with found
D. paron rab-
Philip et a!., 1955), cross-transmission rabbits which are these ticks. Rocky was diagnosed in
109
a woman who resided in Lubbock, Texas in 1985; the tick was possibly contracted from her pet dog (J. R. Johnson, unpubl. data).
On
brown neus) were
1985
R. Johnson, study the four
to
RMSF
different of these
antibody gested infected
and
5 July
1987
body
nods (winter
were
unpubl. data). In the ticks that tested posflat
and
of
located
on
jack rabbits. However, only jack rabbits showed a positive
titer to R. rickettsii that these ticks may the jack rabbits or titers in the jack rabbits
detectable. that our
fall em our
April
(J.
itive four one
30
dog ticks (Rhipicephalus sanguiremoved from dogs from Lubbock fluorescent antibody (FA) positive for
RMSF present
Also, collections
it should were
relatively and spring
low versus
which sugnot yet have that the antiwere not yet
be made
emphasized during
pe-
tick prevalence late summer and
when ticks are more abundant in westTexas; D. B. Pence, unpub!. data). Thus, data on the prevalence of R. rickettsii
in jack rabbits in western conservative. The one IFA titer of spp. could be reflective
Texas
may
be
1 :256 to Borrelia of the agent of
borreliosis; alternatively, it could be a false positive reaction, due to other spirochetes, or a non-specific reaction. Regardless, the low prevalence of antibodies to Borrelia spp. in this absence of dammini or 1985; Steere Westrom et deer
tor parumapertus laboratory strains et al., 1933). Due
lap of distributions variabilis and Ainblyomma ticks more commonly (Harwood umapertus
York
COMMUNICATIONS
Thus, were
(Odocoileus
locality may result from the the normal vectors, Ixodes I. pacificus (Burgdorfer et a!., et a!., 1978; Wa!!is et a!., 1978; a!., 1985), and the absence of spp.)
it is doubtful that detected against
from
study
area.
the antibodies Borrelia spp.
our
that from
jack rabbits in western Texas were B. burgdorferi and it is doubtful Lyme disease spirochete is present
actually that the in this
study area. Although rabbits have been recorded as reservoir hosts for Y. pestis and sylvatic plague is present in western Texas (Kartman et a!., 1966), none of the jack rabbits was positive for antibodies to Y. pestis. Two possible explanations plague antibodies in jack
for the lack of rabbits are that
110
JOURNAL
OF WILDLIFE
DISEASES,
VOL. 26, NO. 1, JANUARY
(1) jack rabbits may not be reservoir hosts for the appropriate flea vectors, or (2) jack rabbits die quickly once exposed to the disease. tailed to
The latter jack rabbits
Francisella
tularensis,
the
of
importance
urban
States vectors
wildlife
site the
the
United
Frieman, L. Hillock,
D.
collecting
the
N.
plague Henke,
Lister, D. VanPelt jack
testing; and M. Po!!ock,
examined
acceptance
or
York,
Lyme
ogy lit
C.
disease
and
W.
Ri Ill HIFLI4, tflqiie
k’ius
spirochetes.
MedIcine
for
LANE,
Jouross
of
I stt
eeislor body.
To qsk’u I Mes Ilr’Ine
otirl
ANt)
legged
1900.
:KM,SN.
us by
lxodes
the
siwutss
A
C.
wood
BAISI9
1985
pw’tju’u.s:
St It,
J.
Derma-
107:
anti24 1-244,
11. A. Gn:sIsnINK,
‘11w western A vector
black
of Borrella
W.
T.
M.
in
24:
California. AND
R.
E.
jack
76:
1120-1122.
K0IILS,
G.
W.
rabbits.
Cox, on
B()WEN.
of R. rick-
antibodies
54:
a
Journal
1-9.
Amblyomma
Reports B.
Spirochetes Ixodidae) from
Observations
from
of Trop-
239-252.
(Acari:
M:MAII0N,
1939.
, C.
Journal
of black-tailed
C.
R.,
AND
tick-borne
1988.
ticks
Reports
R.
of
30:
borreliosis
in serums
Health
Pub-
AN1)
C.
E.
infectious
an
maculatum.
Public
1482-1484.
PHILIP,
AND
W.
L.
1933.
JELLISON.
Rocky mountain spotted fever. Potentialities of tick transmission in relation to geographical occurrence in the United States. American Journal of Tropical
Medicine
13:
341-379.
E. C. PICKENS, D. B. LACKMAN, E. J. BELL, AND F. B. THRAILKILL. 1951. Isolation and characterization of Rocky Mountain spotted fever rickettsiae from the rabbit tick Haernaphysails leporis-palustris. Public Health Reports 66: ,
455-463.
C. B., J. F. BELL, AND C. L. LARSON. 1955. Evidence of infectious diseases and parasites in a peak population of black-tailed jack rabbits in 19:
The
Journal
J.
S. SAMPSON.
of Wildlife
Management
225-233.
RUSSELL,
H.,
linked
ANI)
M.
P.,
N.
MAN, BINM;Il,
STrIIsI:, WISTA.
31$:
SCHMID. 1984. and
Lyme
H.
W.
Enzymeindirect
im-
Jour-
disease.
149; 465-470. 11. (utthw,
M. LI’:vI,
Li. AI.-HAFIoII,
A locus of Rocky New York City. Medicine
for
Diseases
F. F. TEUZAK, LITMAN,
P.
assay assay
nal of Infectious
C.
B. PI.IKAY’I’ls.
imnmne)sorbent
munofluoresceisce
Ii yglene
tick,
New
DONDERS,
American
Diseases
Health
V.
BURGDORFER.
F. , K.
agent
tech’
e,f fluorescent
ed.
York, AND
D.
Hygiene
and lyme
DAVIS.
of
7th
New
Ecology
Complement-fixing
PARKER,
Artter
IdentIfIcation
l)lsease
Infectious
11. S. l,.si:, A. J. LI. ANI)l’:Ieans. tick,
E.
S.t.;o,
rleketlsIt of
test:
EMMONS,
1981.
WIlKINSON,
1 lI’IIII mph
Inc.,
GOLDENBERG,
and
Wildlife
lic
Biol
W.
W.
of
ettsii
Ento-
health,
Recent observations on the epof plague in the United States. Amerof Public Health 56: 1554-1569.
in California.
1961.
of
of
in ticks.
andersonl, Journal
Journal
I.
medicine
PAGAN,
1979.
JAMES.
animal Co.,
NELSON.
focus
T.
and
M.
S. , R.
C.
, AND
in this
.d rk’krttsiae
19: 1010-1014. ,SNI) 1). l.A( RlekcUsl(s
Yale
1970.
R.
453-474.
NI.
1966.
in mammals
the T.
cultivation
Lago-
pp.
L. ,
agents
37: 521 -525.
detection
548
Nevada.
and
Med-
1986.
WILLNER.
pp.
AND
Publishing
idemiology ican Journal
CITED
Isolation
1984.
R.
humans
HUBBERT.
PHILIP,
LITERATURE A.
BARBOUR,
in
KARTMAN,
ical
rejection.
F.,
Macmillan
study. The junior author (DBP) expresses appreciation to Donald J. Forrester who assumed responsibility as Acting Editor for the Journal of Wildlife Diseases for the review of this paper, including its decision on
R.
mology
Osborn, P. Chubb, and A. Hartsell in
rabbits
C.
AND
D.C.,
HARWOOD,
and as a host for the important zoonotic dis-
sylvatic of S. L.
A.,
of Tropical
morphs. In Inventory and monitoring of wildlife habitat, A. Y. Cooperrider, R. J. Boyd, and H. R. Stuart (eds.). U.S. Department of Interior,
the
eases. Undoubtedly, the black-tailed jack rabbit may be a reservoir for additional zoonoses in this locality. We thank W. W. Rossier of the Texas Department of Health for borre!iosis and RMSF testing; T. J. Quail of CDC in Fort for
J.
CHAPMAN,
B.
species
western
and
Washington,
of a common in
as a reservoir of certain
Collins assistance
icine
causative
is presently unknown from the study in Lubbock County in the natural host, prairie dog (Cynomys ludovicianus). The results of this study emphasize
American Journal Hygiene 34: 925-930.
burgdorferi.
is observed in blackthat have been exposed
agent for tularemia (Philip et a!., 1955), thus rendering serological detection of this infection in wild populations difficult. Although reported from counties to the west, northwest and southwest, sylvatic plague
potential
1990
Mountain The New
C. ANI)
11t:RLJ. L.
I). C.
NATIWNSON,
J.
spotted
England
Css;v.
188,
fever
within
Journal
of
1345-1348.
A. C.. T. F. BIsool.;nIt:K. ANt) 1978. Erythema c’Isronicum
S. K. migrans
MAt-Aand
SHORT
Lyme
arthritis:
vector. 3 12-32 WAws,
MAIN,
grans
evidence
of
for
deer (Odocoileus hemionus biancus). Journal of Medical Entomology
and
BROWN,
1978.
Lyme
R.,
1985.
Ixodes
ulation
dynamics
Erythema
of R.
S.
0.
K.
108:
Epidemiology LANE,
pacificus and
KLOTER,
AND
chronicum
Field
arthritis:
Journal D.
colum-
black-tailed
a tick
Epidemiology
111
22: 507-
511. S. E. JR.
American WESTROM,
Journal
1. R. C.,
J.
Epidemiologic
American
COMMUNICATIONS
AND
(Acari: distribution
A. mi-
study of ticks. 108: 322-327. J. R. ANDERSON. Ixodidae): on Columbian
Pop-
K. L.,
WOLFF,
strip
blood
of antibody tis.
Applied
AND
sampling to
B.
W.
HUDSON.
techniques
the plague
Microbiology
organism,
the
detection
Yersinia
28: 323-325.
Received for publication 17 January
Paper
1974.
for
1989.
pes-
